1. Field of the Invention
The present application relates to a lamp tube, and in particular to a light-emitting diode (LED) lamp tube with a driving circuit inside.
2. Description of the Related Art
Currently, there are two types of light-emitting diode (LED) lamp tubes in common use: driver-inside lamp tubes and driver-outside lamp tubes. A driver-inside type lamp tube means that the driver is disposed inside the tube body. Alternatively, a driver-outside type lamp tube means that the driver is disposed outside the tube body.
FIG. 1 is a sectional view of a conventional driver-inside type lamp tube 10. The lamp tube 10 includes a cover 10a made of plastic, a heat sink 10b made of aluminum, a driving circuit 10c, and a light bar including a circuit board 10d and at least a light-emitting element 10e, such as an LED. The driving circuit 10c is disposed in a receiving space R of the heat sink 10b, and the light bar is disposed above the driving circuit 10c and the heat sink 10b. 
However, the receiving space R of the heat sink 10b is about half the volume of the entire lamp tube 10, thus the light-mixing distance D1 from the light-emitting element 10e to the cover 10a is reduced. Consequently, it is usually required that more LEDs be used for improving the illumination of the lamp tube 10, such that the production cost is increased. It should be noted that the heat generated by the light bar and the driving circuit 10c is mainly dissipated through the heat sink 10b. However, since the light bar in the traditional lamp tube 10 is stacked on the driving circuit 10c, the heat from the light bar does not easily dissipate. Therefore, the operation temperature of the driving circuit 10c may increase, such that the usage life of the lamp tube 10 is reduced. For the reasons described above, a driver-inside LED lamp tube which can have great illumination and efficiently dissipate heat from the light bar and the driving circuit 10c is needed.